Reciprocating inertial force balance mechanism of internal-combustion engine

The invention relates to a reciprocating inertial force balance mechanism of an internal-combustion engine. The left side and the right side of a bent axle (6) are respectively connected with a left outer connecting rod (13) and a right outer connecting rod (12), the left outer connecting rod (13) is connected with a left outer piston (2) through a left outer connecting rod bridge (1), the right outer connecting rod (12) is connected with a right outer piston (10) through a right outer connecting rod bridge (11), a left inner connecting rod (5) and a right inner connecting rod (7) are respectively arranged on two sides of the bent axle (6), the left inner connecting rod (5) is connected with a left inner piston (3) through a left inner piston pin (4), and the right inner connecting rod (7) is connected with a right inner piston (9) through a right inner piston pin (8). According to the invention, the parts arrangement of the whole engine is simplified, the pistons are used for replacing the traditional cylinder cover, and the mass of the whole engine is reduced. The outer pistons are used for replacing the cylinder cover, the added outer piston parts ensure that the two pistons operate simultaneously in a cylinder. Compared with the single-piston reciprocating inertial force balance mechanism, the reciprocating inertial force balance mechanism has the advantages that the total distance of the operation of the inner pistons and the outer pistons is enlarged, and the piston stroke of the engine is effectively increased.